scholarly journals Solid State and Solution Study on the Formation of Inorganic Anion Complexes with a Series of Tetrazine-Based Ligands

Molecules ◽  
2019 ◽  
Vol 24 (12) ◽  
pp. 2247 ◽  
Author(s):  
Matteo Savastano ◽  
Celeste García-Gallarín ◽  
Claudia Giorgi ◽  
Paola Gratteri ◽  
Maria Dolores López de la Torre ◽  
...  
Keyword(s):  
Solid State ◽  
Titration Calorimetry ◽  
Salt Bridges ◽  
Anion Receptors ◽  
X Ray Diffraction ◽  
Π Interactions ◽  
Neutral Ligands ◽  
Anion Complexes ◽  
Protonated Molecules

Four molecules (L1–L4) constituted by an s-tetrazine ring appended with two identical aliphatic chains of increasing length bearing terminal morpholine groups were studied as anion receptors in water. The basicity properties of these molecules were also investigated. Speciation of the anion complexes formed in solution and determination of their stability constants were performed by means of potentiometric (pH-metric) titrations, while further information was obtained by NMR and isothermal titration calorimetry (ITC) measurements. The crystal structures of two neutral ligands (L3, L4) and of their H2L3(ClO4)2∙2H2O, H2L4(ClO4)2∙2H2O, H2L3(PF6)2, and H2L3(PF6)2∙2H2O anion complexes were determined by single crystal X-ray diffraction. The formation of anion–π interactions is the leitmotiv of these complexes, both in solution and in the solid state, although hydrogen bonding and/or formation of salt-bridges can contribute to their stability. Evidence of the ability of these ligands to form anion–π interactions is given by the observation that even the neutral (not-protonated) molecules bind anions in water to form complexes of significant stability, including elusive OH− anions.

Charge-by-charge assemblies based on planar anion receptors

2010 ◽  
Vol 83 (1) ◽  
pp. 189-199 ◽  
Author(s):  
Hiromitsu Maeda ◽  
Yohei Haketa
Keyword(s):  
Solid State ◽  
Soft Materials ◽  
Inorganic Anions ◽  
Anion Receptors ◽  
Anion Receptor ◽  
Charged Species ◽  
Efficient Strategy ◽  
Boron Complexes ◽  
Anion Complexes ◽  
Critical Overview

This critical overview proposes a new concept, a charge-by-charge assembly, which consists of alternately stacked positively and negatively charged species, by introducing examples of planar anionic structures in the solid state. The preparation of planar organic anions is not easy; however, complexation of planar anion receptor molecules with inorganic anions is found to be an efficient strategy for constructing them. As suitable motifs, dipyrrolyldiketone boron complexes exhibit various receptor–anion complexes and charge-by-charge assemblies in the solid state. The concept discussed here can be applied to useful soft materials as well as crystals by modifying the anion receptors and cations.

scholarly journals SOLID STATE CHARACTERIZATION OF A NOVEL PHYSICAL INTERACTION (PARACETAMOL-CHLORPHENIRAMINE MALEATE)

2018 ◽  
Vol 10 (1) ◽  
pp. 21
Author(s):  
Iyan Sopyan ◽  
Intan Mutiara Sari ◽  
Insan Sunan K.
Keyword(s):  
Solid State ◽  
Pure Substance ◽  
Physical Interaction ◽  
X Ray Diffraction ◽  
Chlorpheniramine Maleate ◽  
Pharmaceutical Dosage Form ◽  
Pharmaceutical Ingredients ◽  
Ft Ir

Objective: Interactions of active pharmaceutical ingredients (API) as well as pharmaceutical excipients don’t occur in a pharmaceutical dosage form. Base on structures of paracetamol (PCT) and chlorphenamine maleate (CTM), its combination is possible to give a physical interaction in the solid state. This study was conducted to investigate the physical interaction of PCT and CTM in the solid state.Methods: Characterization used the polarization microscope, solubility test, powder x-ray diffraction (PXRD) to observe peak shifting in 2Ɵ angle, and fourier transform infrared spectroscopy (FT-IR) to examine wavenumber shifting.Results: Results of solubility exhibited an increased solubility percentage with increasing concentration. Polarization microscope analysis presented a combination of crystal morphology after the two substances were mixed in an equimolar ratio. The result of melting point determination of each pure substance was 172 °C for PCT, 132 °C for CTM, and 170 °C for the mixture of the two substances in various ratios. Diffractogram showed the shifting at angle 2Ɵ: 20.715, 19.355-23.500 and 21.840, 26.455-20.330 for concentration ratio of PCT: CTM in (132:0.5) and (330:1) respectively and any change in the functional group was observed from infrared spectrum.Conclusion: All evaluation of PCT and CTM in the solid state has exhibited the interaction in solid condition.

scholarly journals NMR crystallography, diffraction and modeling of small organic molecules

2014 ◽  
Vol 70 (a1) ◽  
pp. C1088-C1088
Author(s):  
Luís Miguel Monteiro Mafra
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Crystal Packing ◽  
Computational Study ◽  
Chemical Shifts ◽  
Hybrid Approach ◽  
X Ray Diffraction ◽  
Structure Solution ◽  
Nmr Crystallography

Solid-state NMR (SSNMR) is a powerful atomic-level characterization technique able to study the local chemical environment of a nucleus in crystalline/amorphous solids. Toward a better understanding of how small molecules self-assemble in the solid-state and reorganizes to produce its hydrate/anhydrous forms, an experimental SSNMR, X-ray diffraction (XRD), and computational study of the supramolecular assemblies of selected small pharmaceuticals is presented. The effect of crystal packing on the 1H and 13C chemical shifts including nonconventional hydrogen bonds, pi···pi and CH···pi contacts, is studied through computer simulations. It will be shown that NMR chemical shifts are sensitive detectors of hydration/dehydration states in highly insoluble antibiotics.[1] Recently, SSNMR became an important gadget in the process of crystal structure solution in powders. This is a non-trivial task and using powder XRD methods alone may often lead to the wrong structure solution. In this talk, a new hybrid approach for structure determination of crystalline solids, will be presented, based on the combination of SSNMR, XRD and an ensemble of computational-assisted structure solution tools including a genetic algorithm based on evolution-inspired operators repeatedly applied to populations of possible crystal structure solutions that evolve to eventually produce the best new offspring candidates. Such methodologies are successfully applied to challenging cases involving multiple component crystals composed by flexible molecules such as a trihydrate β-lactamic antibiotic [2] and an azole-based co-crystal featuring an hydrogen bond network of α-helixes involving NH···N/CH···π intermolecular interactions. ACKNOLEDGEMENTS: Supported by Fundação para a Ciência e a Tecnologia (FCT), Portuguese National NMR Network (RNRMN), CICECO (PEst-C/CTM/LA0011/2013), FEDER, COMPETE, and University of Aveiro. FCT is greatly acknowledge for the consolidation grant IF/01401/2013.

scholarly journals Exploiting the Synergy of Powder X-ray Diffraction and Solid-State NMR Spectroscopy in Structure Determination of Organic Molecular Solids

2013 ◽  
Vol 117 (23) ◽  
pp. 12258-12265 ◽  
Author(s):  
Dmytro V. Dudenko ◽  
P. Andrew Williams ◽  
Colan E. Hughes ◽  
Oleg N. Antzutkin ◽  
Sitaram P. Velaga ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Structure Determination ◽  
Solid State Nmr ◽  
Molecular Solids ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solid State Nmr Spectroscopy

Anion Complexes with Tetrazine-Based Ligands: Formation of Strong Anion−π Interactions in Solution and in the Solid State

2016 ◽  
Vol 55 (16) ◽  
pp. 8013-8024 ◽  
Author(s):  
Matteo Savastano ◽  
Carla Bazzicalupi ◽  
Claudia Giorgi ◽  
Celeste García-Gallarín ◽  
Maria Dolores López de la Torre ◽  
...  
Keyword(s):  
Solid State ◽  
Π Interactions ◽  
Anion Complexes

The solid-state emmissive chalcone (2E)-1-(5-chlorothiophen-2-yl)-3-[4-(dimethylamino)phenyl]prop-2-en-1-one

2015 ◽  
Vol 71 (9) ◽  
pp. 783-787 ◽  
Author(s):  
Rafael E. Rodríguez-Lugo ◽  
Neudo Urdaneta ◽  
Bruno Pribanic ◽  
Vanessa R. Landaeta
Keyword(s):  
Solid State ◽  
Theoretical Calculations ◽  
Photon Absorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Biological Target ◽  
Related Compounds

Orange rectangular blocks suitable for X-ray diffraction analysis were obtained for the previously reported [Ahmad & Bano (2011).Int. J. ChemTech Res.3, 1470–1478] title chalcone, C15H14ClNOS. This solid-emissive chalcone exhibits a planar structure and the bond parameters are compared with related compounds already described in the literature. The determination of the structure of this chalcone is quite relevant because it will play an important role in theoretical calculations to investigate potential two-photon absorption processes and could also be useful for studying the interaction of such compounds with a biological target.

scholarly journals Structure Determination of Molecular Solids from Powder X-ray Diffraction Data

2014 ◽  
Vol 70 (a1) ◽  
pp. C1557-C1557
Author(s):  
Kenneth Harris
Keyword(s):  
Solid State ◽  
Structure Determination ◽  
Solid State Nmr ◽  
Structural Information ◽  
Powder Xrd ◽  
Computational Techniques ◽  
Molecular Solids ◽  
X Ray Diffraction ◽  
X Ray

Structure determination of organic molecular solids from powder X-ray diffraction (XRD) data [1] is nowadays carried out extensively by researchers in both academia and industry, and the development of new methodology in this field has made particularly significant impact in the pharmaceuticals industry within the last 20 years or so. However, although software for carrying out each stage of the procedure for structure determination from powder XRD data is now readily accessible and relatively straightforward to use, it is essential that the results from such structure determination calculations are subjected to careful scrutiny to confirm that the final structure obtained is actually correct. In this regard, it can be particularly advantageous to augment the analysis of the powder XRD data and to assist the scrutiny of the structural results by considering complementary structural information derived from other experimental and computational techniques. Techniques that can be particularly valuable in this regard include solid-state NMR spectroscopy, energy calculations (either on individual molecules or periodic crystal structures), vibrational spectroscopies, and techniques of thermal analysis (e.g. DSC and TGA). The lecture will give an overview of the current "state of the art" in the structure determination of organic materials from powder XRD data, giving emphasis [2,3] to the opportunities to enhance the structure determination process by making use of information derived from other experimental (especially solid-state NMR) and computational techniques. Recent results will be presented, with emphasis on raising issues of relevance to research on pharmaceutical materials.

scholarly journals Construction of pillar[4]arene[1]quinone–1,10-dibromodecane pseudorotaxanes in solution and in the solid state

2020 ◽  
Vol 16 ◽  
pp. 2954-2959
Author(s):  
Xinru Sheng ◽  
Errui Li ◽  
Feihe Huang
Keyword(s):  
Solid State ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Guest Molecule ◽  
X Ray Diffraction ◽  
Guest Molecules ◽  
X Ray ◽  
Π Interactions ◽  
Host Molecules ◽  
Complexation Stoichiometry

We report novel pseudorotaxanes based on the complexation between pillar[4]arene[1]quinone and 1,10-dibromodecane. The complexation is found to have a 1:1 host–guest complexation stoichiometry in chloroform but a 2:1 host–guest complexation stoichiometry in the solid state. From single crystal X-ray diffraction, the linear guest molecules thread into cyclic pillar[4]arene[1]quinone host molecules in the solid state, stabilized by CH∙∙∙π interactions and hydrogen bonds. The bromine atoms at the periphery of the guest molecule provide convenience for the further capping of the pseudorotaxanes to construct rotaxanes.

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